* clutter/clutter-texture.c:
(clutter_texture_get_preferred_width),
(clutter_texture_get_preferred_height),
(clutter_texture_set_property),
(clutter_texture_get_property),
(clutter_texture_class_init),
(clutter_texture_init): Add the new :keep-aspect-ratio property
to ClutterTexture; when set to TRUE the texture will return a
preferred width maintaining the aspect ratio with the given height
and a preferred height maintaining the aspect ratio with the
given width. This allows to set the width or the height and have
the texture automatically request the height or the width respectively
while maintaining the aspect ratio of the original image.
* tests/test-script.json: Update to test the new :keep-aspect-ratio
property.